Frequency multiplier for ultra high frequencies



June 25, 1935. c, w HANSELL 2,005,782

FREQUENCY MULTIPLIEIR FOR ULTRA HIGH FREQUENCIES Filed NOV. 3, 1952 2 Sheets-Sheet l INVENTOR- CLARENCE W. HANSELL ATTORNEY- June 25, 1935. c, w. HANSELL FREQUENCY MULTIPLIER FOR ULTRA HIGH FREQUENCIES Filed Nov. 3, 1932 2 Sheets-Sheet 2 INVENTOR- CLARENCE w. HANELL BY ATTORNEY- Patented June 25, 1935 PATENT OFFICE FREQUENCY MULTIPLIEB. FOB ULTRA HIGH FREQUENCIES Clarence W. Hansell, Port Jefferson, Long Island, N. Y., assignor toRadio Corporation of America, a corporation of Delaware Application November 3,1932, Serial No. 641,020

12 Claim. (01. 250-36) This invention relates to the generation of high frequency oscillations in electron-discharge devices, and in .particular relates to a method of and apparatus for increasing the frequency of a master oscillator.

One of the objects of the present invention is to enable the frequency multiplication of oscillations in a simple and efficient manner.

Essentially, the invention consists of a cathode ray type of vacuum tube in which potentials that are supplied by a master oscillator affect the electron stream of the tube to cause a circular movement of the electrons over a specially designed anode of the tube. The anode is provided with targets and openings alternately arranged around a circle to permit passage of the electronstream through the anode at intervals in such manneras to set up the equivalent of a very high frequency oscillating current.

An important characteristic of this arrangement is that radiation takes place directly from pulsating groups of electrons without entailing the usual losses which are inherent in the use of load circuits and their associated wire connec-' tions.

A feature of the invention lies in the particular construction of the anode which enables the generation of the high frequency currents and permits ready access to the anode for cooling purposes.

Other vobjects, features and advantages will appear in a subsequent detailed description.

In the accompanying drawings wherein like parts are designated by like reference characters, Figures 1 and 2 disclose signalling circuits for the generation and transmission of high frequency oscillations. The circuitsof these figures differ from each other only in the particular method of mounting the anode structure. Figure.3 illustrates, diagrammatically, a cross sectional view of the cathode ray tube and reflector along'the line aa of Figures 1 and 2.

Although the principles of the present invention are hereinafter described only in connection with transmitting circuits, it is to be distinctly understood that the scope of the invention is not limited thereto since the invention is equally applicable for use in any and all types of oscillation generator circuits.

Referring to Figure 1 in more detail, there is shown a cathode ray type of vacuum tube comprising an envelope Ill, which may be of glass or other suitablematerial, having located therein a cathode ll supplied with heating current from a source l2 in circuit with variable resistance 22.

Cathode II is operated at a temperature sufliciently high to cause the emission of a large number of electrons. Arranged around the cathode and surrounding it are focusing or deflecting electrodes l3 which are ordinarily supplied with a negative direct current potential of such a value as to cause the stream of electrons from the cathode 'l I to be focused; upon a small spot at one end of anode M. Anode I4 is operated at a high positive potential by means of source of potential 23 and has the end just referred to provided with a metal cap having segments of metal l5 separated from one another by open spaces, the segments extending radially from the center in a manner similar to the spokes of a wheel. On the side of the anode away from the cathode is placed a second electrode l6 which is operated at either zero or negative potential with respect to the cathode ll.

The anode I4 in Figure 1 is shown brought outside the envelope Ill, in a manner similar to that employed with water cooled vacuum tubes now in common use. This makes it possible to attach to the anode a cooling flange I1 as shown in the drawings. Of course, cooling may be accomplished, if desired, by means of a liquid circulated past the anode.

The operation of the arrangement shown in the drawings is as follows:

The focusing or deflecting electrodes l3 have supplied to them three phase radio frequency energy from a master oscillator. There are numerous ways known in the art for converting single phase alternating current energy into three phase energy or for generating three phase radio frequency energy directly; consequently, this feature will not be shown herein since it forms no part of the present invention exceptin mined by the amount of radio frequency potential applied to the three deflecting electrodes, andthis potential is adjusted so that the spot moves around a circle having a diameter equal to approximately half the diameter of the anode 14. The stream of electrons in sweeping over the spoked or segmented end of anode I4 will be alternately caught on the segments IE or allowedto pass through the apertures between the segments. When the electrons pass through the apertures their inertia carries them toward the negative electrode i 6, but the electric fleld between anode l4 and electrode [6 gives them an acceleration toward anode it which will quickly bring their velocity to zero and pull them back again to the anode. The time required for the electrons to pass between anode M toward electrode l6 and return should correspondto the time of one half cycle of the frequency multiplied energy which it is desired to produce, and.

this then may be adjusted by adjusting the potentials of anode It and electrode iii. Since the groups of electrons coming through anode M, and returning to it again, constitute the equivalent of a radio frequency current; radiation will take place directly from the tube and this radiation may be used for signalling purposes or for any other purpose for which extremely high radio frequency energy is desired.

A preferable arrangement for signalling purposes is to mount the vacuum tube in the focus of reflector IS in a manner which will give sharp directivity to the radiation produced. Figures 1 and 2 show only a fragmentary portion of such a reflector in order not to complicate the drawings.

modulation of the oscillations in conductor 21.

Figure 3 shows diagrammatically a cross sectional view of the vacuum tube It in the focus of the reflector l8 along the line H of Figures 1 and 2.

It will be understood, of course, that the invention is not limited to the use of three phase energysince any number of phases, from two upwards, may, if desired, be used, with an appropriate number of deflecting electrodes.

From the foregoing, it will be apparent that the invention is susceptible of being modified to meet different conditions encountered in its use, and it is, therefore, aimed to cover by the appended claims all modifications within the spirit and scope of the present invention.

I claim:

1. The method of generating high frequency oscillations which includes producing an electron stream, applying a plurality of electrical fields out of phase with respect to one another to the electron stream in a direction transverse to the longitudinal axis of the stream whereby the stream is cyclically deflected to travel along a circular path, interrupting, at intervals, free movement of said stream and reversing the direction of travel of those portions of the stream which are not interrupted.

2. The method of generating high frequency oscillations by frequency multiplication which includes producing an electron stream, applying a plurality of electrical fields out of. phase with respect to one another to the electron stream in a direction traversing the longitudinal axis of the stream whereby the stream is cyclically deflected to travel along a circular path, interrupting, at intervals, free movement of said stream and reversing the direction of travel of the uninterrupted portions of said stream whereby the time of travel of the uninterrupted electrons for a complete reversal from the point of interruption corresponds to substantially the time of one half cycle of the frequency multiplied energy.

3. In an electrical system, an oscillation generator circuit comprising an evacuated envelope having located therein an electron emitting catlrode, an electron repelling electrode, and an anode intermediate said cathode and electron repelling electrode, means for supplying a high positive potential to said anode with respect to said cathode and electron repelling electrode said anode being provided with apertures to permit the passage therethrough of groups of electrons from said cathode, and a plurality of deflecting elec-' trodes supplied with alternating currents out of phase with respect to one another spaced around the path of travel of said electrons for influencing the movement of said electrons.

l. In an electrical system utilizing alternating electrical currents, an electron discharge device having an electron emitting cathode, a source of potential for heating said cathode for causing a stream of electrons to flow, a substantially circularly shaped anode provided with spaced apertures therein for permitting groups of electrons to flow therethrough, means for supplying a positive potential to said anode with respect to said cathode, a plurality of deflecting electrodes spaced around the path of said electron stream and supplied with alternating current potentials out of phase with respect to one another for causing circular movement of said electron stream upon said anode, an electron repelling electrode, said anode being located intermediate said cathode and electron repelling electrode, and means for supplying a negative potential to said electron repelling electrode with respect to said anode for reversing the direction of travel of the electrons passing through the apertures of said anode.

5. A system as defined in claim 4 characterized in this, that said deflecting electrodes are located near said cathode.

6. In an electrical system, an oscillation generator circuit comprising an evacuated envelope having located therein an electron emitting cathode, an electron repelling electrode, and an anode intermediate said cathode and electron repelling electrode, said anode being provided with apertures to permit the passage therethrough of groups of electrons from said cathode, and a plurality of deflecting electrodes supplied with alternating currents out of phase with respect to one another spaced around the path of travel of said electrons for influencing free movement of said electrons, and a reflector for controlling the direction of radiation of said groups of electrons.

7. An electrical signalling system having, in combination, a reflector, a cathode ray oscillation generator tube in the focus of said reflector comprising an evacuated envelope having therein an electron emitting cathode, an electron repelling electrode, and an anode intermediate said cathode and electron repelling electrode, said anode being provided with apertures to permit the passage therethrough of groups of electrons from said cathode, means for supplying a high positive potential to said anode with respect to said cathode and electron repelling electrode and a plurality of deflecting electrodes supplied with alternating currents out of phase with respect to one another spaced around the path of travel of said electrons for influencing their motion,

and means external of said envelope for cooling said anode.

8. In an electrical system, an electron discharge device having an elongated evacuted envelope comprising therein an electron emitting cathode at one end thereof, an electron repelling electrode at the other end thereof, and an anode intermediate said cathode and electron repelling electrode and located at the center of said envelope, said anode being provided with spaced apertures to permit groups of electrons to pass therethrough, means for supplying a positive potential to said anode with respect to said cathode and repelling electrode, and a plurality of deflecting electrodes near said cathode and supplied with alternating current out of phase with respect to one another to cause electrons emanating from said cathode to move in a circular path on said anode, apparatus in circuit with said means for modulating the oscillations set up in said discharge device, and means for transmitting the modulated oscillations.

9. In a circuit arrangement wherein a cathode ray tube is located in the focal plane of a reflector, the method of radiating energy which consists in generating groups of oscillating electrons in said tube which of themselves constitute energy in the form of an electrical oscillating current not carried by any material conductor, and reflecting said energy.

10. In an electrical system, an oscillation generator circuit comprising an evacuated envelope having located therein an electron emitting cathode, an electron repelling electrode, and an anode intermediate said cathode and electron repelling electrode, said anode being supplied with a high positive potential with respect to said last two electrodes and being provided with apertures to permit the passage therethrough of groups of electrons from said cathode, three deflecting electrodes spaced around the path of travel of said electrons 120 degrees apart from one another for influencing the movement of said electrons, and a source of three phase current connected to said reflecting electrodes for supplying same with alternating current.

11. A system in accordance with claim 3 characterized in this, that said anode is located at the center of said envelope.

12. A system as defined in claim 4, characterized in this, that said deflecting electrodes are substantially located on a circle and surround said cathode.

CLARENCE W. HANSELL. 

